CN106785912A - Semiconductor laser and preparation method thereof - Google Patents

Abstract

The invention discloses a semiconductor laser, which comprises a substrate and a lower confinement layer, a lower waveguide layer, a quantum well active region, an upper waveguide layer and an upper confinement layer sequentially stacked on the substrate; the semiconductor laser It also includes a hole blocking layer interposed between the lower waveguide layer and the quantum well active region. According to the semiconductor laser of the present invention, the hole blocking layer is prepared between the lower waveguide layer and the quantum well active region, thereby effectively blocking holes from the quantum well active region to the lower waveguide layer and the N-type region side of the lower confinement layer The leakage improves the carrier injection efficiency, thereby improving the performance of the semiconductor laser. The invention also discloses a manufacturing method of the semiconductor laser.

Description

Semiconductor laser and manufacturing method thereof

technical field

The invention belongs to the technical field of semiconductor optoelectronic devices, and in particular relates to a semiconductor laser and a manufacturing method thereof.

Background technique

Gallium nitride (GaN) and its series of materials (including aluminum nitride, aluminum gallium nitride, indium gallium nitride, and indium nitride) are characterized by their large band gap, wide spectral range (covering the entire range from ultraviolet to infrared), and resistance to It has good high temperature and corrosion resistance, and has great application value in the fields of optoelectronics and microelectronics. Gallium nitride-based lasers are a very important gallium nitride-based optoelectronic device. Since the light waves emitted by them are in the visible light band, gallium nitride-based lasers are widely used in high-density optical information storage, projection display, laser printing, and underwater communication. , Sensing and activation of biochemical reagents and medical treatment have important application value.

In GaN-based lasers, it is mainly divided into three parts: the active region formed by single quantum well or multiple quantum wells, the N-type region on one side of the active region that provides electrons for the active region, and the active region The P-type region on the other side provides holes for the active region. By applying an external bias voltage, electrons and holes are injected into the active region in a direction perpendicular to the junction plane to recombine and generate light. The feedback cavity is formed by the cleavage mirror at both ends of the side, so that the light generated by the recombination of electrons and holes resonates continuously in the cavity and forms a standing wave whose wavefront is parallel to the mirror. However, in GaN-based semiconductor lasers, hole leakage is prone to occur on the side of the N-type region, which causes the problem of lower carrier injection efficiency and slope efficiency of the laser.

Contents of the invention

In order to solve the above-mentioned problems in the prior art, the present invention provides a semiconductor laser and its manufacturing method. The hole blocking layer in the semiconductor laser can effectively block hole leakage, thereby improving the injection of carriers. efficiency.

In order to achieve the above-mentioned purpose of the invention, the present invention has adopted following technical scheme:

A semiconductor laser, comprising a substrate and a lower confinement layer, a lower waveguide layer, a quantum well active region, an upper waveguide layer and an upper confinement layer sequentially stacked on the substrate; the semiconductor laser also includes an interposed A hole blocking layer between the lower waveguide layer and the quantum well active region.

Further, it also includes a quantum barrier layer interposed between the hole blocking layer and the quantum well active region.

Further, an electron blocking layer is also included; wherein, the electron blocking layer is interposed between the quantum well active region and the upper waveguide layer or between the upper waveguide layer and the upper confinement layer.

Further, the material of the hole blocking layer is any one of N-type gallium nitride, N-type indium gallium nitride, and N-type aluminum gallium nitride that has been unintentionally doped or N-type doped.

Further, when the material of the hole blocking layer is any one of N-type doped N-type gallium nitride, N-type indium gallium nitride, and N-type aluminum gallium nitride, the doping concentration is 1 ×10 ¹⁷ cm ^-3 to 1×10 ²⁰ cm ^-3 , the donor impurity is at least one selected from silicon and germanium.

Further, the doping method of the donor impurity is selected from any one of uniform doping or gradient doping; wherein, the gradient doping includes linear change doping and step change doping.

Further, the shape of the upper restriction layer is planar or ridge-shaped.

Further, the quantum well active region includes n quantum well structures, 1≤n≤12; wherein, the quantum well structure includes a quantum well single layer and a quantum well layer stacked in a direction away from the substrate Quantum barrier monolayer.

Further, the semiconductor laser further includes an N-type gallium nitride material layer interposed between the substrate and the lower confinement layer.

Another object of the present invention is to provide a semiconductor laser manufacturing method according to any one of the above, including: providing a substrate; sequentially stacking layers on the substrate to prepare a lower confinement layer, a lower waveguide layer, a spacer Hole barrier layer, quantum well active region, upper waveguide layer and upper confinement layer.

The present invention prepares a hole blocking layer between the lower waveguide layer and the quantum well active region, thereby effectively preventing holes from leaking from the quantum well active region to the lower waveguide layer and the N-type region side of the lower confinement layer; thus Compared with the semiconductor laser without the hole blocking layer in the prior art, the prepared semiconductor laser has improved carrier injection efficiency, thereby improving the performance of the semiconductor laser.

Description of drawings

The above and other aspects, features and advantages of embodiments of the present invention will become more apparent through the following description in conjunction with the accompanying drawings, in which:

Fig. 1 is a schematic structural view of a semiconductor laser according to Embodiment 1 of the present invention;

Fig. 2 is a schematic structural view of the quantum well active region according to Embodiment 1 of the present invention;

3 is a simulation diagram of the hole concentration distribution inside the semiconductor laser according to Embodiment 1 of the present invention under the condition that the current density is 1000A/cm ² ;

Fig. 4 is the semiconductor laser according to comparative example 1 of the present invention under the condition that the current density is 1000A/cm ² , the simulation diagram of the hole concentration distribution inside it;

Fig. 5 is the electroluminescent spectrogram according to the sample A of comparative example 2 of the present invention;

Fig. 6 is the electroluminescence spectrogram of sample B according to comparative example 2 of the present invention;

FIG. 7 is a schematic structural view of a semiconductor laser according to Embodiment 2 of the present invention;

Fig. 8 is a schematic structural view of a semiconductor laser according to Embodiment 3 of the present invention.

detailed description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the specific embodiments set forth herein. Rather, the embodiments are provided to explain the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention for various embodiments and with various modifications as are suited to particular intended uses. In the drawings, the shapes and dimensions of elements may be exaggerated for clarity, and the same reference numerals will be used throughout to designate the same or like elements.

It will be understood that, although the terms "first", "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

Example 1

FIG. 1 is a schematic configuration diagram of a semiconductor laser according to this embodiment.

Specifically referring to FIG. 1 , the semiconductor laser according to this embodiment includes a substrate 1, and an N-type GaN material layer 2, a lower confinement layer 31, a lower waveguide layer 32, and a hole blocking layer that are sequentially stacked on the substrate 1. 33 . Quantum barrier layer 34 , quantum well active region 4 , electron blocking layer 51 , upper waveguide layer 52 and upper confinement layer 53 .

Specifically, as shown in FIG. 2 , the quantum well active region 4 includes at least one quantum well single layer 41 and at least one quantum barrier single layer 42 alternately stacked, and the quantum well single layer 41 and the quantum barrier layer 34 adjacent, and the quantum barrier single layer 42 is adjacent to the electron blocking layer 51; in the quantum well active region 4, the number of the quantum well single layer 41 and the quantum barrier single layer 42 are the same, and the number n of the two All are controlled within the range of 1≤n≤12; in this embodiment, the value of n is 3. That is to say, in the quantum well active region 4, at least one quantum well structure is included, and each quantum well structure includes a quantum well single layer stacked in a direction away from the substrate 1 41 and a quantum barrier monolayer 42 .

More specifically, in this embodiment, the three quantum well single layers 41 are respectively recorded as the first quantum well single layer 411, the second quantum well single layer 412 and the third quantum well single layer 413, correspondingly, The three quantum barrier single layers 42 are respectively referred to as the first quantum barrier single layer 421, the second quantum barrier single layer 422 and the third quantum barrier single layer 423, and the three quantum well single layers 41 and the three quantum barrier single layers 42 Alternately arranged on the quantum barrier layers 34 to form a structure as shown in FIG. 2 .

In this embodiment, the material of the substrate 1 is gallium nitride; the thickness of the N-type gallium nitride material layer 2 is 2000 nm, and it is doped with silicon at a concentration of 3×10 ¹⁸ cm ⁻³ ; the lower limit The material of layer 31 is N-type aluminum gallium nitride with a thickness of 1300nm, and it is doped with silicon at a concentration of 3×10 ¹⁸ cm ^-3 ; the material of lower waveguide layer 32 is N-type indium gallium nitride with a thickness of 100nm left and right, and it has been unintentionally doped; the hole blocking layer 33 is made of N-type gallium nitride with a thickness of 15nm, and it is doped with silicon at a concentration of 2×10 ¹⁹ cm ^-3 ; the quantum barrier layer 34 The material is gallium nitride, the thickness is about 15nm, and it has been unintentionally doped.

In the quantum well active region 4, the material of the quantum well single layer 41 is indium gallium nitride, the material of the quantum barrier single layer 42 is gallium nitride, and each quantum well single layer 41 and each quantum barrier single layer 42 They are all unintentionally doped; the thickness of each single quantum well layer 41 is about 2.5nm, and the thickness of each single quantum barrier layer 42 is about 15nm.

The material of the electron blocking layer 51 is P-type aluminum gallium nitride with a thickness of 20nm, and it is doped with magnesium at a concentration of 5×10 ¹⁹ cm ^-3 ; the material of the upper waveguide layer 52 is indium gallium nitride with a thickness of 100nm , and it is doped with magnesium at a concentration of 1×10 ¹⁸ cm ^-3 ; the material of the upper confinement layer 53 is P-type aluminum gallium nitride with a thickness of 500 nm, and it is doped with magnesium at a concentration of 1×10 ¹⁹ cm ^-3 of magnesium.

It is worth noting that, in this embodiment, the shape of the upper confinement layer 53 is planar, so that even the semiconductor laser has a gain waveguide structure.

According to the hole blocking layer 33 that the semiconductor laser of the present embodiment possesses effectively blocked holes from leaking to one side of structures such as the downward waveguide layer 32 and the lower confinement layer 31 from the quantum well active region 4, improved the carrier The injection efficiency; and the electron blocking layer 51 that this semiconductor laser possesses also effectively blocks electrons from leaking to one side of structures such as the upper waveguide layer 52 and the upper confinement layer 53 from the quantum well active region 4, thereby further improving the carrying capacity. The injection efficiency of flow electrons improves the performance of the semiconductor laser.

Hereinafter, the method of manufacturing the semiconductor laser of this embodiment will be described in detail.

The manufacturing method of the semiconductor laser according to the present embodiment includes the following steps:

In step one, a substrate 1 is provided.

In this embodiment, the substrate 1 is specifically a gallium nitride substrate. Of course, other materials such as sapphire, silicon carbide, silicon, or spinel can be used, and details will not be repeated here.

In step 2, an N-type gallium nitride material layer 2 , a lower confinement layer 31 , a lower waveguide layer 32 and a hole blocking layer 33 are prepared layer by layer on the substrate 1 .

Specifically, first, a layer of N-type gallium nitride with a thickness of 2000 nm is grown on the substrate 1 by metal-organic compound chemical vapor deposition process (abbreviated as MOCVD process), and it is doped with a concentration of 3×10 ¹⁸ cm ^-3 Silicon; the specific growth temperature is controlled between 900° C. and 1100° C., and the growth pressure is controlled between 200 Mbar and 500 Mbar to prepare the N-type gallium nitride material layer 2 .

Wherein, the N-type gallium nitride material layer 2 can ensure good bonding between other structures grown subsequently and the substrate 1; of course, the N-type gallium nitride material layer 2 can be removed if the process conditions permit. It is also possible to directly grow other structures on the substrate 1 .

Then, a layer of 1300 nm thick N-type aluminum gallium nitride is grown on the N-type gallium nitride material layer 2 as the lower confinement layer 31 by MOCVD process, and silicon is doped therein at a concentration of 3×10 ¹⁸ cm ⁻³ ; The specific growth temperature is controlled between 1000° C. and 1200° C., and the growth pressure is controlled between 100 Mbar and 300 Mbar.

Third, grow a layer of N-type InGaN with a thickness of about 100 nm on the lower confinement layer 31 as the lower waveguide layer 32 by MOCVD process, wherein the N-type InGaN is unintentionally doped; the specific growth temperature is controlled as Between 700°C and 900°C, the growth pressure is controlled between 200Mbar and 500Mbar.

Finally, a layer of N-type gallium nitride with a thickness of about 15 nm is grown on the lower waveguide layer 32 as the hole blocking layer 33 by MOCVD process, and it is doped with silicon at a concentration of 2×10 ¹⁹ cm ^-3 ; the specific growth temperature The control is between 600°C and 900°C, and the growth pressure is controlled between 200Mbar and 500Mbar.

In this way, the N-type region positioned at one side of the quantum well active region 4 has been prepared, and the prepared hole blocking layer 33 can effectively prevent holes from passing from the quantum well active region 4 to the N-type region. Leakage on one side improves the carrier injection efficiency, thereby improving the performance of the semiconductor laser.

In step three, the quantum barrier layer 34 and the quantum well active region 4 are prepared layer by layer on the hole blocking layer 33 .

Specifically, first, a layer of gallium nitride with a thickness of about 15 nm is grown on the hole blocking layer 33 as the quantum barrier layer 34 by using the MOCVD process, wherein the gallium nitride is unintentionally doped; the specific growth temperature is controlled at 600° C. Between 900°C, the growth pressure is controlled between 200Mbar and 500Mbar.

Then, three layers of indium gallium nitride and three layers of gallium nitride are grown on the quantum barrier layer 34 by MOCVD process as the quantum well single layer 41 and the quantum barrier single layer 42 respectively; wherein, the first quantum well single layer 411, the first quantum well The barrier single layer 421, the second quantum well single layer 412, the second quantum barrier single layer 422, the third quantum well single layer 413 and the third quantum barrier single layer 423 are sequentially stacked to form the quantum well active region 4; The first quantum well single layer 411, the second quantum well single layer 412, and the third quantum well single layer 413 have a thickness of 2.5nm, and the first quantum barrier single layer 421, the second quantum barrier single layer 422, and the third quantum barrier single layer The thickness of the layer 423 is 15nm, and the gallium nitride in the above layers is unintentionally doped; the specific growth temperature is controlled between 600°C-900°C, and the growth pressure is controlled between 200Mbar-500Mbar.

In step four, an electron blocking layer 51 , an upper waveguide layer 52 and an upper confinement layer 53 are prepared layer by layer on the quantum well active region 4 .

Specifically, a layer of P-type aluminum gallium nitride with a thickness of about 20 nm is grown as the electron blocking layer 51 on the quantum well active region 4, that is, the third quantum barrier single layer 423 by MOCVD process, and doped with a concentration of 5×10 ¹⁹ cm ^-3 of magnesium; the specific growth temperature is controlled between 800°C and 1000°C, and the growth pressure is controlled between 100Mbar and 300Mbar.

Then grow a layer of 100nm-thick InGaN on the electron blocking layer 51 as the upper waveguide layer 52 by MOCVD process, and it is doped with magnesium at a concentration of 1×10 ¹⁸ cm ⁻³ ; the specific growth temperature is controlled at 700 ℃～900℃, and the growth pressure is controlled between 200Mbar～500Mbar.

Finally, a layer of 500nm-thick P-type aluminum gallium nitride is grown on the upper waveguide layer 52 by MOCVD process as the upper confinement layer 53, and it is doped with magnesium at a concentration of 1×10 ¹⁹ cm ^-3 ; the specific growth temperature is controlled between 700°C and 900°C, and the growth pressure is controlled between 200Mbar and 400Mbar.

In this way, the P-type region opposite to the N-type region located on the other side of the quantum well active region 4 is prepared, and the prepared electron blocking layer 51 can effectively prevent electrons from entering the quantum well active region 4. The leakage to one side of the P-type region further improves the carrier injection efficiency, thereby further improving the performance of the semiconductor laser.

In order to verify the effect of the hole blocking layer 33 in the semiconductor laser of this embodiment, the following comparative examples 1 and 2 were designed.

Comparative example 1

In the semiconductor laser of Comparative Example 1, the hole blocking layer described in Example 1 is not included, and the rest of the structure is the same as that of the semiconductor laser described in Example 1.

The semiconductor laser of Example 1 and the semiconductor laser of Comparative Example 1 were respectively tested for their internal hole concentration distribution under the condition that the current density was 1000A/cm ² , and the results are shown in Fig. 3 and Fig. 4 respectively; wherein, In FIG. 3 and FIG. 4 , c both represent the hole concentration, that is, the logarithm of the hole concentration when the ordinates both take 10 as the base.

Comparing the curves in Figure 3 and Figure 4, it can be clearly seen that the hole concentration in the lower confinement layer and the lower waveguide layer of the semiconductor laser described in Example 1 is lower, that is to say that the semiconductor laser in Example 1 The hole blocking layer does effectively prevent holes from leaking from the side of the N-type region of the quantum well active region to the lower confinement layer, lower waveguide layer and other structures, thereby improving the injection efficiency of carriers. The semiconductor The performance of the laser is improved.

Comparative example 2

The following two groups of structures are included in this comparative example:

The first group: on the basis of the semiconductor laser of embodiment 1, a blue light quantum well active region is set between the lower waveguide layer and the hole blocking layer; the blue light quantum well active region at this time is called The first blue light quantum well active region, so obtain sample A (in order to distinguish the quantum well active region of two different color lights, the quantum well active region described in embodiment 1 is called the first green light quantum well active region area); that is to say, the structure of the sample A is a substrate, an N-type GaN material layer, a lower confinement layer, a lower waveguide layer, a first blue light quantum well active region, a hole blocking layer, Quantum barrier layer, first green light quantum well active region, electron blocking layer, upper waveguide layer and upper confinement layer.

The second group: on the basis of the semiconductor laser of comparative example 1, a blue light quantum well active region is also set between the lower waveguide layer and the quantum barrier layer; the blue light quantum well active region at this time is called The second blue light quantum well active region, so obtain sample B (in order to distinguish the quantum well active region of two different color lights, the quantum well active region described in Comparative Example 1 is called the second green light quantum well active region area); that is to say, the structure of the sample B is a substrate, an N-type GaN material layer, a lower confinement layer, a lower waveguide layer, a second blue light quantum well active region, a quantum barrier layer, a second Two green light quantum well active regions, an electron blocking layer, an upper waveguide layer and an upper confinement layer.

Electroluminescence spectra were tested for sample A and sample B respectively, and the test results are shown in Fig. 5 and Fig. 6 respectively.

Comparing Figure 5 and Figure 6, it can be clearly seen that under the condition of the same current density, the luminous intensity of the first blue quantum well active region in sample A is significantly lower than that of the second blue quantum well active region in sample B. The luminous intensity of the region shows that after the hole blocking layer is added in sample A, the number of holes leaked from the first green quantum well active region to the first blue quantum well active region decreases, that is, the hole blocking layer It plays a role in preventing holes from leaking from the quantum well active region (that is, the first green light quantum well active region in sample A) to the side of the N-type region such as the downward waveguide layer and the lower confinement layer.

Example 2

In the description of Embodiment 2, the similarities with Embodiment 1 will not be repeated here, and only the differences with Embodiment 1 will be described. The difference between Embodiment 2 and Embodiment 1 is that, referring to FIG. 7 , the positions of the electron blocking layer 51 and the upper waveguide layer 52 in the semiconductor laser of this embodiment are higher than those of the semiconductor laser in Embodiment 1. In other words, in the semiconductor laser of this embodiment, the electron blocking layer 51 is interposed between the upper waveguide layer 52 and the upper confinement layer 53 .

Correspondingly, in the manufacturing process of the semiconductor laser in this embodiment, the difference from the manufacturing process of the semiconductor laser in Embodiment 1 is that in step 4, on the quantum well active region 4 layer by layer The upper waveguide layer 52 , the electron blocking layer 51 and the upper confinement layer 53 are prepared.

Example 3

In the description of Embodiment 3, the similarities with Embodiment 1 will not be repeated here, and only the differences with Embodiment 1 will be described. The difference between Embodiment 3 and Embodiment 1 is that, referring to FIG. 8, the semiconductor laser of this embodiment has a ridge waveguide structure, that is, in the semiconductor laser of this embodiment, the shape of the upper confinement layer 53 is a ridge. .

Specifically, the difference between the manufacturing method of the semiconductor laser of this embodiment and the manufacturing method of the semiconductor laser in Embodiment 1 is that, on the basis of the manufacturing method of the semiconductor laser of Embodiment 1, the following steps are also included:

In step five, the upper confinement layer 53 is etched to make the upper confinement layer 53 in a ridge shape.

Of course, the ridge-shaped upper confinement layer 53 described in this embodiment is not limited to the structure in which the upper waveguide layer 52 is interposed between the electron blocking layer 51 and the upper confinement layer 53 described in Embodiment 1, and it is also applicable As described in Embodiment 2, the electron blocking layer 51 is interposed between the upper waveguide layer 52 and the upper confinement layer 53 .

It should be noted that, in the foregoing embodiments 1-3, when the material of the hole blocking layer 33 is the same as that of the quantum barrier layer 34, the difference is only that the hole blocking layer 33 is doped, and the quantum barrier layer When 34 is not doped, the quantum barrier layer 34 can also be omitted, or it can be considered that the hole blocking effect is realized by doping the material of the quantum barrier layer 34, without the need to set a separate hole blocking layer 33 . On the other hand, when the material of the hole blocking layer 33 is the same as that of the lower waveguide layer 32, the effect of hole blocking can also be realized by doping the upper half of the lower waveguide layer 32 without setting a separate The hole blocking layer 33. Of course, a combination of the above two situations is also possible, subject to achieving the hole blocking effect.

Certainly, the material of each structure in the semiconductor laser according to the present invention is not limited to the above-mentioned embodiment, the material of the lower confinement layer 31 can also be N-type AlGaN/GaN superlattice; the lower waveguide layer 32 The material of the N-type gallium nitride or N-type aluminum gallium nitride can also be used; the material of the hole blocking layer 33 can also be N-type indium gallium nitride or aluminum gallium nitride; the material of the quantum barrier layer 34 can also be N Indium gallium nitride or N-type aluminum gallium nitride; In the quantum well active region 4, the material of the quantum barrier single layer 42 can also be indium gallium nitride or aluminum gallium nitride; the material of the upper waveguide layer 52 can also be It is P-type gallium nitride or P-type aluminum gallium nitride; the material of the upper confinement layer 53 can also be P-type aluminum gallium nitride/gallium nitride superlattice or transparent conductive oxide, including zinc oxide, magnesium oxide, oxide Binary metal oxides such as tin, cadmium oxide, and indium oxide, or ternary metal oxides such as indium tin oxide, aluminum zinc oxide, gallium zinc oxide, indium zinc oxide, and magnesium zinc oxide, or ternary metal oxides such as indium gallium zinc oxide .

Corresponding to the above-mentioned materials, in the manufacturing method of the present invention, the preparation process of each structural layer is not limited to the MOCVD process described in the above-mentioned embodiment. When the material of each structural layer is the above-mentioned transparent conductive oxide, it can also be It is prepared by magnetron sputtering deposition process, electron beam evaporation deposition process, and pulsed laser deposition process. When the material does not belong to the above-mentioned transparent conductive oxide, it can also be prepared by molecular beam epitaxy growth process and atomic layer deposition process.

While the invention has been shown and described with reference to particular embodiments, it will be understood by those skilled in the art that changes may be made in the form and scope thereof without departing from the spirit and scope of the invention as defined by the claims and their equivalents. Various changes in details.

Claims (10)

1. a kind of semiconductor laser, including substrate and the lower limitation that lamination is set successively over the substrate Layer, lower waveguide layer, Quantum well active district, upper ducting layer and upper limiting layer；Characterized in that, described half Conductor laser also includes the hole barrier being located between the lower waveguide layer and the Quantum well active district Layer.

2. semiconductor laser according to claim 1, it is characterised in that also described including being located in Quantum barrier layer between hole blocking layer and the Quantum well active district.

3. semiconductor laser according to claim 2, it is characterised in that also including electronic barrier layer； Wherein, on the electronic barrier layer is located between the Quantum well active district and the upper ducting layer or is described Between ducting layer and the upper limiting layer.

4. the semiconductor laser according to any one of claims 1 to 3, it is characterised in that the sky The material on cave barrier layer be through unintentional doping or n type gallium nitride through n-type doping, N-type InGaN, Any one in N-type aluminium gallium nitride alloy.

5. semiconductor laser according to claim 4, it is characterised in that when the hole blocking layer Material be any one in n type gallium nitride, N-type InGaN, N-type aluminium gallium nitride alloy through n-type doping When planting, doping concentration is 1 × 10¹⁷cm^-3~1 × 10²⁰cm^-3, donor impurity is selected from least in silicon, germanium Kind.

6. semiconductor laser according to claim 5, it is characterised in that the donor impurity is mixed Miscellaneous mode is selected from any one in Uniform Doped or gradient doping；Wherein, the gradient doping includes linear Change doping, step-like change doping.

7. the semiconductor laser according to any one of claims 1 to 3, it is characterised in that on described The shape of limiting layer is in plane or ridge.

8. the semiconductor laser according to any one of claims 1 to 3, it is characterised in that the amount Sub- trap active area includes n quantum well structure, 1≤n≤12；Wherein, the quantum well structure include according to The SQW individual layer and a quantum set away from the direction lamination of the substrate build individual layer.

9. the semiconductor laser according to any one of claims 1 to 3, it is characterised in that described half Conductor laser also includes the n type gallium nitride material layer being located between the substrate and the lower limit layer.

10. the preparation method of a kind of semiconductor laser as described in any one of claim 1 to 9, it is special Levy and be, including：

One substrate is provided；

Lamination prepares lower limit layer, lower waveguide layer, hole blocking layer, SQW and has successively over the substrate Source region, upper ducting layer and upper limiting layer.